package com.example.git1;
import java.util.Scanner;
public static void main(String[]args){
        boolean falg=true;
        while(falg){
        Scanner scanner=new Scanner(System.in);
        System.out.println("请输入用户名");
        String username=scanner.next();
        System.out.println("请输入密码");
        String password=scanner.next();
        System.out.println("请输入邮箱");
        String post=scanner.next();
        try{
        zh(username,password,post);
        System.out.println("注册成功");
        falg=false;
        }catch(Exception e){
        System.out.println(e.getMessage());
        System.out.println("注册失败");
        }
        }
public static void zh(String username,String password,String post){
        if(!(username.length()>=2&&username.length()<=4)){
        throw new RuntimeException("用户名长度为2，3，4");
        }
        if(!(password.length()==6&&isDate(password))){
        throw new RuntimeException("密码为6位的纯数字");
        }
        int i=post.indexOf('@');//获取对应字符的下标
        int j=post.indexOf('.');
        if(!(i>0&&j>i)){
        throw new RuntimeException("邮箱的@必须在.前面");
        }
        }
public static boolean isDate(String src){
        char[]chars=src.toCharArray();
        for(int i=0;i<chars.length;i++){
        if(chars[i]< '0'||chars[i]>'9'){
        return false;
        }
        }
        return true;
        }
        }
